Nicholas Lemke weighed in and more than 300 pounds when he woke up one day and decided. Just like that.

"I wanted to make a change in my life," said the 29-year-old Lyons man.

It was April 2008. He bought a bike and started riding. A friend invited him to run, so Lemke tagged along. Then winter came.

"I thought, what else can I do? I joined the YMCA and started swimming," Lemke recalled. "Then I thought, why don't I put it together and do a triathlon?"

Two years later, Lemke had lost 108 pounds. He put 15 pounds back on, after he realized he had gotten too thin, and has maintained his new weight, as well as found a passion for long-distance races. He started competing in 2010 in endurance races, primarily bicycling, and in a few triathlons. In 2011 and 2012, he did strictly triathlons.

It took him a year to prepare, but Lemke participated in the world-renowned Ironman Triathlon, when one was held in Sept. 9, 2012, in Madison, Wisc. The races include a 2.4-mile swim, an 112-mile bike ride and a 26.2-mile marathon run – all consecutive. To be a finisher, athletes have to complete the course in 17 hours. Lemke's time was 14 hours, 31 minutes and 39 seconds.

"I didn't race. I went there for the experience," Lemke said, adding that he took the advice of a fellow athlete, who told him, "'Have fun, and take it all in. You can race in the next one.'"

Lemke has signed up for another Ironman competition this year, Aug. 25 in Louisville, Ky.

Lemke said at his current weight of 218, he is "big for a triathlete. They are usually 150 to 160 pounds," he said. He swims in the middle of the pack, but the bike is his event.

Lemke races across Michigan and in other states now. It's an every weekend-thing for him, he said.

"I'm single, no kids, no restrictions, which is why I can do this. Friends with wives and kids have said, 'You might as well do it now,'" he said, adding that his girlfriend since November is "new to this world."

Lemke said his life in changed in a few ways. He's definitely healthier.

"At the gym, I walk around holding a 50-pound dumbbell in each hand and think, how did I lug this extra weight around?" he said.

He's also learned a lot about himself, pushing himself to explore new limits.

"I am a determined person," he said. "I like to see what I can do next. I'm never satisfied, and I want to see how far I can push myself."

Lemke said he still has to be watchful of how he eats. Sometimes he slips.

Page 2 of 2 - "But the next day is a new day," he said. "I wish it was as easy to lose as it is to put back on."

Lemke said he gets asked for advice from people who want to know how they can do what he did.

"When it gets hard, don't give up," he said he tells them. "There are bad days and good days, but remember it's just one day. And tomorrow is another day."

When he finished the Ironman challenge, Lemke said he was awed by the support of the community, including people he hadn't talked to since high school, who posted congratulations on Facebook, sent emails and text messages.

"I was really overwhelmed how many people cared," he said. "I'm just one person, and they took time out of their day."

Jennifer Roundtree, who has known Lemke for 12 years – they worked together at Michigan One Credit Union – said the change has made him "a lot happier." The two supported one another during some difficult personal times, and became closer. Roundtree travels with Lemke when she can to take photos. Last year Lemke encouraged her to take up running, and accompanied her in four 5K races.

"He ran with me so I'd finish. That's friendship. He took the time to help me, to encourage me. He was right there," she said. "I wanted him to be proud of me like I was proud of him."

Mike Ralston, Lemke's friend since fourth grade at Twin Rivers School in Lyons, said the change in his friend physically, from before to after, is "amazing, just ridiculous." Emotionally, Lemke has always been loyal and would do anything for anyone, but now he is much more confident in himself, Ralston said. The impact he has had on those around him "who are along for the ride" is the real life-changer.

"It's the inspiration you get from the things he's doing, for the people near and dear to him," Ralston said. "If you think about the distances, the Ironman event itself, it's crazy. He's my best friend, and to see him accomplish a goal he's wanted to do, words can't express."

Ralston said he is proud of his long-time friend.

"I'm a 30-year-old man, and he makes me cry," Ralston said. "He was a big boy when he started this, and he's a totally different person. It'll get you."